I tried the VoIP exclusive back in the dark ages of 3G via mobile Skype with limited success. Wireless data was not fast enough nor reliable enough for consistent call quality. 4G has improved on both, but occasionally farts out. In these days of LTE, carriers are starting to roll out VoLTE, which is essentially VoIP over LTE. So, then the question is, why not just use a handset without a voice plan and route calls via an LTE hotspot?
My idea works great this time around so long as I stay within city limits. It becomes unworkable when travelling out to the rural areas, which I have done. Downgrading to 2G service left me without Internet and without voice calling. I did carry with me a backup GSM phone with voice and text, just in case. But, I've come to realize that relying on Google Voice as my main number requires me to stay put in town.
Earlier tonight, I tried talking to my wife via Google Hangouts voice call from my tablet through a 4G hotspot (HSPA+). As I drove home, our call quality was rather lousy, probably because handoffs from tower to tower aren't smooth enough on GSM. I should attempt the same via LTE. If carriers are starting to roll out VoLTE, then perhaps travelling from cell to cell is smoother. I am waiting for Karma to finally ship their LTE hotspot to experiment, but that's not until April.
Without a phone, I'm at a loss as what to do. I could make and receive calls from my tablet using Google Hangouts; but, things get tricky. I'd have to carry the tablet, a headset, hotspot, and backup phone everywhere. I suppose it would make sense to have a tablet with built-in mobile service. This way you only need one device, make that two devices, because you'll need a Bluetooth headset,
Yes, this is very much like having a regular mobile phone, with the exception that you are not paying for voice and SMS. I think data only is a better value than bundled voice, text, and data. The bundling is an upsell because you figure that you're getting them all cheaper. Ultimately, however, you really only need data nowadays, which can provide the same unlimited texting and calling. So, you're paying extra for unlimited use of something you use less and less.
Of course, we still need legacy phone service as a backup line. But, I see the day coming when handsets will mainly be data devices like tablets. It's feasible for city folk. I think I would be fine with an everyday tablet phone and a "travelling phone".
With all of that said, I think I am going to have to cough up some money for a new phone. Wi-Fi only calling simply isn't fitting in with my current business needs. Someday, when I become a virtual assistant or some other work-at-home professional, maybe I can go all Wi-Fi. But for now, it isn't practical. I shall have to re-evaluate when I can get my hands on an LTE device.